Tach not working on Mercury Outboard

[Jim Shavers]

I have a 1987 Mercury 150 hp outboard. The tachometer quit working
yesterday. Does anyone know how to test the tach to see if it has gone
bad. Also, where does the tach connect to on the engine? I also plan to
check the wiring to see if I have a loose connection somewhere but have
not had time yet.

Thanks

Jim
Email: jrsh...@hiwaay.net

[Ken Stovesand]

I had a similar problem with my 1989 merc 200. The tach stops when the charging rectifier module goes out.
Suggest you check the voltage at the battery during operation to insure that you are still charging. Hope you
find the problem.

Regards,

Ken S.

[W.G. Sutherland]

Jim Shavers wrote:

> I have a 1987 Mercury 150 hp outboard. The tachometer quit working

>yesterday. Does anyone know how to test the tach to see if it has gone.

Look for the rectifier. It is a small square component with 2 yellow
wires a grey wire and a red wire connected. Move the grey wire from
the terminal with the yellow wire to the other terminal with the
yellow wire and see if the Tach works if so replace the rectifier if
not check your harness for any breaks and have some one put a test
tach on the system.

Best Regards
willy gee
aj_com...@sunshine.net
In the Heart of Sunny Uptown Madeira Park